At a recent talk at the TED Conference, Bill Gates let us in on a secret. If he could have anything, this is what the world's richest man wants. An energy source that is cheaper than coal and has zero carbon dioxide emissions. He said that this would improve the prospects for the human race more than any breakthrough he could imagine.

Why does Gates think that? It's because he knows that the world is going to consume lots more energy in the years ahead. For example, in the next decade the number of cars on the road will double from one billion to two billion. Overall we'll consume 50 percent more energy. Why? Well, Americans and our SUVs are partly to blame, but really, it's about the rise of the rest.

The world will add one billion people over the next two decades. If these people in fast-growing companies like China and India have dreams like the American dream -- houses, cars, TVs, Big Macs, then as the "New York Times'" columnist Tom Friedman says, we will need another planet.

Today we power our lives with fossil fuels. Oil, coal and natural gas provide 80 percent of our energy. But do we have enough energy to keep growing at this pace? And are we harming the ecosystem in which we live?

Already sea levels are rising, the Arctic ice caps are melting, and scientists' projections about climate change are becoming more alarming. That's why Bill Gates makes his wish for an energy that is cheap and clean.

In this hour, and in a "Time" magazine essay, we're going to see who's doing best at energy production around the world. We'll look at technologies of the future and best practices of today. We'll go to a country that gets 75 percent of its electricity from a source that emits zero carbon dioxide. And we'll explore a new energy technology that's cheap, cleaner than coal and right in our own backyard.

But first I'll take you to a country that was almost completely dependent on energy from the Middle East 40 years ago. Now this nation is totally energy independent. How did they do it? Let's find out.

(BEGIN VIDEOTAPE) ZAKARIA (voice-over): In 1973, Denmark was in big trouble. The Yom Kippur war led to an oil embargo and the Danes were 99 percent dependent on foreign energy, much of it from the Middle East. So they bend driving on Sundays and told people to turn off their lights.

In America as well the 1970s brought a sense of crisis.

JIMMY CARTER, FORMER PRESIDENT OF THE UNITED STATES: I am tonight setting a clear goal for the energy policy of the United States.

ZAKARIA: President Jimmy Carter encouraged conservation and installed solar panels on the roof of the White House. But those panels eventually came down and our resolve to go green faded. Meanwhile, Denmark doubled down on green energy, and now, incredibly, they are completely energy independent. They were helped greatly after discovering oil and gas in the North Sea.

TOM FRIEDMAN, COLUMNIST, NEW YORK TIMES: They looked at that crisis and they've said never again.

ZAKARIA: Tom Friedman of the "New York Times," author of "That Used to Be Us," tells the story of Denmark in "Hot, Flat, and Crowded". His book about going green.

(On camera): What was the striking thing to you about Denmark?

FRIEDMAN: Little Denmark had produced a whole set of export industries around clean, renewable energy.

ZAKARIA (voice-over): After the oil crisis, the Danish government subsidized renewable energy and levied big taxes on energy use and fossil fuels. Gasoline costs about $8 a gallon these day.

Did all of that kill economic growth? No. Since 1973, Denmark's economy has slightly outpaced the economies that now make up the eurozone.

FRIEDMAN: What you get is enormous innovation because all your industries produce renewable energy that can sell in their marketplace at a decent price. And once they do it for little Denmark, they looked around the world and said well, we can kill it in America, we can kill it in China, and that's why two of the biggest energy companies in the world for wind and biofuels are Danish.

ZAKARIA: One Danish powerhouse is Vestas. Builder of almost 1/5 of the world's wind turbine capacity and employ a roughly 19,000 people worldwide. Vestas produced green jobs before they were trendy.

DITLEV ENGEL, VESTAS CEO: We learned that energy dependence is something you should take very, very seriously.

ZAKARIA: Ditlev Engel, Vestas' CEO, notes that the Danes get almost 30 percent of their electricity from the wind, more than any other developed nation. By 2020, they pledge to get half of their electricity from wind power. And by 2050, they promise to be completely fossil fuel free. ENGEL: It's not about what's possible from its ecological point of view, it is all down to leadership and determination.

ZAKARIA: Samso is a sign of what's possible. It's a sleepy island between the North Sea and the Baltic Sea where you might see as many cows as people. But don't let the rustic setting fool you. Samso is on the cutting edge of energy efficiency. All of its electricity comes from the wind and overall Samso actually has a negative carbon footprint. Farmers like Johan Trunber (ph), a clean energy entrepreneurs. Owning shares of the island's wind turbines.

ENGEL: The wind turbines on the sea they produce 18 million kilowatts together so I see that's nearly the biggest export we have from the island that electricity.

ZAKARIA: Ditlev Engel says the U.S. could be a wind power house, too. Think of those windy prairies in the great plains.

ENGEL: When I discover that these resources are not being harvested, I really get amazed. Because to me, that would be like going for instance to Saudi Arabia and not real forward.

BJORN LOMBORG, AUTHOR, "THE SKEPTICAL ENVIRONMENTALIST": Fundamentally, wind is still more expensive.

ZAKARIA: Denmark's Bjorn Lomborg, author of "The Skeptical Environmentalist," says that the Dane's energy prices are the highest in the world. He also points out that Vestas has run into trouble. It plans to cut almost 4,000 jobs in 2012. Including 1/5 of its U.S. workforce. And wind power overall, he points out, is still more expensive than the cheapest fossil fuels.

LOMBORG: As long as it's not competitive, I still think we should say let's invest more in getting the next generations of wind turbines to be cheaper rather than putting up lots and lots of them that we know are inefficient right now.

ZAKARIA (on camera): But people say the only way you get the cost to go down is by deploying large amounts of existing technology in scale.

LOMBORG: There's definitely an argument for scale. But it's still more expensive even after we produce lots of it.

ZAKARIA (voice-over): Another big challenge, storing wind power, to use when the wind isn't blowing.

In fact all of the world's currency battery capacity can store only 10 minutes worth of the world's annual energy demand according to Bill Gates.

One idea, take the excel energy that you can't score from the wind turbines and use it to charge the batteries for electric cars. One company called Better Place already has charging stations all over Denmark, connected to the grid, where you can swap out your dead battery for a live one in just minutes. But with few electric cars on the road, that solution may take a while to catch on.

(END VIDEOTAPE)

ZAKARIA: Denmark's wind driven approach to energy is compelling. But wind power can be intermittent, more expensive than fossil fuels and requires a big commitment.

Next we'll look at another carbon free technology which has truly remarkable potential.

(COMMERCIAL BREAK)

ZAKARIA: Take a look at the timer on your screen. When it reaches zero in 14 and a half seconds, the sun will have emitted enough energy to power the earth for an entire day.

Here's another way to look at it. We could power the entire world if we covered less than 3 percent of the Sahara Desert with solar panels. The power of the sun is truly remarkable. And surprisingly, no country is better at harnessing that power than a cloudy and cold land, Germany.

How did that happen? We went there to shed some light on the subject.

(BEGIN VIDEOTAPE)

ZAKARIA (voice-over): May 25, 2012 was a historic day for Germany and for the entire planet. At midday, solar panels in Germany set a world record, supplying one-third of the nation's electricity demand. Germany is certainly not known for its sunshine, yet the nation boasts 1/3 of the entire world's solar capacity.

DR. THOMAS KNEIP, CENTROSOLAR VICE PRESIDENT: There's no other country in the world that comes anywhere close to that level.

ZAKARIA: Dr. Thomas Kneip is a vice president at CENTROSOLAR, one of Germany's leading solar companies. He says the nation's attitude towards energy was profoundly changed by the Soviet Union's nuclear power plant meltdown at Chernobyl which directly affected many Germans.

KNEIP: I remember I was riding by bike as fast as I could back home because there was a cloud coming and everyone told you, don't get in the rain because there were toxic particles in it.

ZAKARIA: In the wake of the disaster, Germany's environmental movement blossomed. With political groups like the Green Party gaining momentum.

KNEIP: The Green Party and the major parties, the Conservatives and Democratic, took on environmental issues in their program.

ZAKARIA: One of the key measures parliament passed was the so-called feed-in-tariff. If you're a German homeowner with solar panels on your roof, you can feed your energy back into the grid and your power company is required to pay you for that energy for 20 years.

(On camera): Was it after the feed-in-tariffs were inactive that solar really took off in Germany?

KNEIP: Yes. Yes. Germans, on those things, they don't install solar systems just for saving the world. They install them because they give you a nice return on your investment.

ZAKARIA (voice-over): Since 2000 solar installations in Germany have jumped over 600 fold. Proving the boom for the solar industry. And even for some suburban families. Families like the (INAUDIBLE) who live outside of Berlin.

(INAUDIBLE) gets about $3,000 every year for the energy that his rooftop panels feedback into the grid. In seven years he'll have made enough money to cover the cost of buying the panels. After that, it's all profit.

KNEIP: We will make a profit, but that's not the main reason. The main reason is that we are independent in the future from all these huge energy companies.

ZAKARIA: As solar has become more and more popular in Germany, the cost has plummeted and world wide it's the same story.

KNEIP: In the last 20 years, with every doubling of capacity installed, the cost of solar has gone down 20 percent. And that has accelerated over the last two years.

ZAKARIA: Solar panels also have the advantage that you can put them where the energy is needed, say, in a new town or a remote factory without having to lay power lines. But solar energy has its critics.

LOMBORG: Germany is definitely leading but it's not something they should be boastful about.

ZAKARIA: Author Bjorn Lomborg and other critics of solar point out that solar energy still provides only 5 percent of Germany's electricity and less than 1 percent of its total energy.

Remember that world record day in May I told you about when solar provided a third of Germany's electricity? That was a very sunny day. What's more, solar subsidies are blamed for driving up energy costs for non-solar customers.

(On camera): The problem here is in order to do all these things, you need subsidies, you need taxes. And people look at that and say this is just going to produce lots of distortions and inefficiencies.

FRIEDMAN: They're absolutely right, Fareed. Let's get rid of it all, let's get rid of the oil depletion allowance, let's get rid of all the subsidies for coal and for nuclear. And then let's let everybody compete.

ZAKARIA (voice-over): Still even in green friendly Germany, solar subsidies have caused a political backlash. The main solar subsidy is gradually being phased out. But Angela Merkel's government made unscheduled cut of roughly 30 percent last spring. Some German solar companies have run into trouble in recent years, filing for bankruptcy.

KNEIP: Right now we have a consolidation phase in the industry. Quite frankly there is not a single company that is making decent profits right now.

ZAKARIA: One reason, Chinese solar companies are over supplying the market with cheaper panels helped by their own government subsidies. And even some of them are taking big losses.

FRIEDMAN: China has made solar energy so cheap, as cheap as tennis shoes and undershirts basically. The fact is Germany is actually using now so much more solar energy but it may not be German companies that are benefiting from.

(END VIDEOTAPE)

ZAKARIA: The potential for solar energy is huge, but it is still expensive, limited in scale and like wind, you still need some way to store it when the sun isn't shining.

What about nuclear power? Doesn't it solve all these problems? Next we'll visit a country that gets 75 percent of its electricity from nuclear and it's never had a major accident.

(COMMERCIAL BREAK)

ZAKARIA: We've looked at wind and solar energy. Well, what happens when the wind stops flowing and the sun stops shining? One country with minimal access to natural resources turned to nuclear energy before the 1973 oil crisis awakened the world. Today, France generates 75 percent of its electricity by splitting apart atoms and it's no coincidence that France has cheap electricity, and as you'll see, the French are apparently so thoughtful they even recycle their nuclear waste.

(BEGIN VIDEOTAPE)

ZAKARIA (voice-over): On August 6th, 1945, the world was changed by Little Boy. That was the code name for the first ever atomic weapon dropped on Hiroshima and killing in the end more than 100,000 people. Out of this terrible tragedy, an industry sprung up. One that has been surrounded in mystery and conflict.

HERVE MACHENAUD, GENERATION AND ENGINEERING HEAD, ELECTRICITY DE FRANCE: Around nuclear, there is ideology. I would say even religions. And there is a feeling that there is few people which are dealing with the life of the humanity.

ZAKARIA: Herve Machenaud is the head of generation and engineering for Electricity de France, the state owned utility company. Thanks to nuclear energy, France makes $3 billion every year as the world's largest net exporter of electricity. MACHENAUD: The only mass way of producing electricity, whatever the season, the time, the hour in the world, without producing CO2 is nuclear. There is no other way.

ZAKARIA: Here in Flamanville, a traditional French town on the Normandy coast, nuclear energy seems to be a part of life. That's just the way things are says this retired roofer.

UNIDENTIFIED MALE (Through Translator): There are people who don't like it, it doesn't bother me. It's great. Without them here, we'd be dead.

ZAKARIA: Dead because the nuclear sector is the biggest employer here. It may be old France, but Flamanville also represents the future for French nuclear power.

This is the site for the EPR, the European Pressurized Reactor. A third generation reactor that EDF says will be more powerful and safer than old models.

MACHENAUD: We included a lot of new devices which came from feedback experience from Three Mile Island accident, Chernobyl accident, even now we include new devices to answer the Fukushima accident.

ZAKARIA: But the construction of this rethought reactor is running four years behind schedule and it's set to cost almost twice it's original budget and contrary to popular opinion, it is that cost problem, not safety, that is at the heart of the nuclear issue, says, "New York Times" columnist Tom Friedman.

(On camera): There are a lot of people in the green energy business who look at nuclear with a lot of suspicion.

FRIEDMAN: The thing holding it back right now is price. If you want to build a one gigawatt nuclear plant, it's at least a $10 billion proposition. That's really why it hasn't gone ahead. That said, I don't see how we could scale without a nuclear component in the mix. And I think we've done cleanly and safely so I am not an opponent of nuclear energy.

ZAKARIA (voice-over): The day-to-day operating costs are low and the French have streamlined upfront costs by using just seven design models to build their entire 58 reactor fleet says Machenaud.

MACHENAUD: The key of the cost in industry is standardization. The EDF program has been built at half the cost of the Germany one and a third of the cost of the Japanese one because of the industrial model.

ZAKARIA: The US has historically used several plant designs that we have started to standardized and whereas we store our nuclear waste, France recycles it.

JORDAN: The spent fuel is then cooled inside queen bath (ph) and then puts inside a basket.

ZAKARIA: All of France's used fuel ends up in pools like this.

JORDAN: What you see here are the baskets where the spent fuel is stored. In the spent fuel 96 percent of the material is recyclable.

ZAKARIA: About 17 percent of France's electricity comes from reused nuclear fuel. Before she can get to the storage facility where the non-recyclable parts of fuel are, Jordan passes through a radiation contamination check.

JORDAN: It says that we have 0.1 micro fiber.

ZAKARIA: Having only absorbed .005 the amount of radiation of a transatlantic flight, Haroline makes it to the storage hole.

JORDAN: Under my both feet here I have the equivalent quantity of what is left after one year of a prediction of a nuclear power plant.

FRIEDMAN: I wish we didn't have to have nuclear. In an ideal world I'd love to replace it with full renewables. But I worry if we shut all this down what would happen on the price side.

ZAKARIA: But shutting down is exactly what the new French administration has talked about doing.

The socialist president Francois Hollande has promised to reduce France's share of nuclear from 75 percent to 50 percent by 2025. So far only one of France's reactors is set to be decommissioned.

(END VIDEOTAPE)

ZAKARIA: Nuclear energy accounts for 20 percent of America's electricity production. If there's a future for nuclear power, as a constant carbon-free companion to renewable, it would look more like the French model and there are promising new technologies that might do much better than the French model with regard to safety, costs and waste. But they're still on the drawing board.

Coming up next, we'll explore what is the biggest energy revolution right now, and it's happening right here at home. We'll be right back.

(COMMERCIAL BREAK)

ZAKARIA: We've traveled the world to see how other countries have focused on wind, solar and nuclear power. Currently all those forms of energy have upsides and downsides. But what if we could innovate our way to a more effective energy technology right here at home. We may already have done that.

(BEGIN VIDEOTAPE) ZAKARIA (voice-over): Down in Louisiana off the Gulf of Mexico, something strange is happening. A few years ago as American natural gas supplies were dwindling, a company called Cheniere Energy built a facility to import liquid natural gas from other countries. Now, just a few years later, it's converting the facility to export gas.

(On camera): So you build this terminal to import liquid natural gas.

CHARIF SOUKI, CEO, CHENIERE ENERGY: Yes.

ZAKARIA: A funny thing happens in the next few years.

SOUKI: Well, it wasn't so funny.

ZAKARIA (voice-over): It wasn't funny for Charif Souki, the CEO of Cheniere Energy because his company almost went bankrupt. What happened? The low levels of natural gas production in America suddenly gave way to a boom. Thanks to shale gas.

(On camera): How big is the shale gas revolution in America?

SOUKI: It's stupefyingly large.

ZAKARIA: Shale gas is a form of natural gas extracted from shale rock, deep underground through a special drilling process called hydraulic fracturing or fracking.

In 2000 shale gas accounted for only 2 percent of all natural gas. In 2012 it accounts for 32 percent. That's because America happens to be the Saudi Arabia of shale gas with big shale deposits over much of the country.

And here's the kicker. When you burn natural gas to produce energy, it emits roughly half as much greenhouse gas as coal.

FRIEDMAN: Natural gas is the perfect complement to wind and solar. Not only does it emit half as much CO2 as coal, but you can just turn it on and off when the sun goes down or the wind stops blowing to make tremendous inroads in reducing our carbon emissions.

ZAKARIA: In fact, we already have reduced emissions. In 2011, greenhouse gas emissions in the U.S. were 9 percent lower than 2007 levels. One reason was that demand for transportation fuel was down, but another major force according to the government was our switch from coal to natural gas.

In 2000, natural gas accounted for only 22 percent of the electricity we get from fossil fuels. Compared to 73 percent for coal. Through July of 2012, it accounted for 46 percent and coal was down to 53 percent. That dramatic switch didn't happen because of our suddenly greener outlook on life. A main reason it happened is because natural gas now costs about the same as coal.

LOMBORG: Fracking shows us if we get the price below, for instance, coal, everyone will adopt it, you will get a dramatic shift, you will get reduction in CO2 emissions because it's a greener alternative and you'll get cheaper prices.

ZAKARIA: But there are definitely some downsides to shale gas and plenty of controversy.

Here's how fracking works. Millions of gallons of water mixed with sand and chemicals is shot down a well as deep as 10,000 feet below ground. The water hits the shale with a lot of pressure causing it to fracture and release natural gas back up the well.

FRIEDMAN: What you do with that water afterwards is very important. Can you treat it, clean it again and reuse it? Do you just leave it in pools lying around? Do you inject it into the ground in ways that can cause earthquakes which is a real problem or seep into aquifers.

ZAKARIA: Another challenge? Containing gas leaks during the extraction process, especially methane which is a potent green house gas.

(On camera): Many of these allegations have been contested. For example, sometimes the gas that has ended up in people's water pipes comes from wells that they drill in their backyards not from fracking. But the EPA is working on a comprehensive study of fracking as it should. This is an industry that needs regulation.

FRIEDMAN: I think it's very important that we get a grand bargain between the environmental community and the natural gas industry that says we're going to do this right. By the way, it's in the huge interest of the natural gas industry, because if I turn on my tap and a flame comes out, you know, or I got natural gas coming up my toilet, I'm telling you, they will shut this industry down.

ZAKARIA (voice-over): That will be a shame for our economy. Shale gas is cheap energy and cheap energy fuels growth, from lowering our heating bills to cutting the costs of shipping and making things.

PricewaterhouseCoopers says the shale gas boom could spark a manufacturing renaissance creating one million manufacturing jobs by 2025. And think about how cheap natural gas could lower carbon emissions in China and India where they are building four coal fire power plants a week with disastrous environmental effects not to mention the thousands of people who died because of coalmining.

LOMBORG: What really matters is what China and India does. And they want more energy and they want it cheaper. So what we have to make sure is that we focus on innovation to make green energy sources so cheap they will switch. We have shown the way through the fracking of gas, but we still need to move further, we need to make green energy, solar panels, wind turbines even cheaper. And once they become cheaper than fossil fuels, everyone will buy them.

ZAKARIA: Once Charif Souki in Cheniere Energy have their natural gas terminal up and running, they'll be able to move energy to China and India for a good profit and create jobs here at home. (END VIDEOTAPE)

ZAKARIA: We've shown you many different approaches to energy in this hour, but we're saving the best for last. Next, we'll show you what is arguably the greenest, safest and most profitable form of energy. This is something that tree huggers and CEOs are both going to love.

The main suspect in a mass shooting today is dead. Police in Brookfield, Wisconsin, say this man, Radcliff Haughton, was found dead at the scene and he appears to have killed himself.

This is where the shooting happened. The full service spa outside Milwaukee. Witnesses say the gunman walked inside at opening time and shot seven people. Three of them died.

The numbers continue to climb in the deadly fungal meningitis outbreak. According to data released by the CDC, 23 people are now tied to the outbreak. There are 285 total cases including three joint infections. Most patients got sick after being given contaminated steroid injections used for back and neck pain.

And former United States Senator George McGovern has died. His family made the announcement today saying McGovern died before dawn at a hospice in South Dakota.

A decorated bomber pilot in World War II, McGovern was elected to the House in the 1950s and then to the Senate in the 1960s. Here's a 1972 Democratic nominee for president. He lost to Richard Nixon.

George McGovern was 90.

Those are your headlines this hour. I'm Don Lemon keeping you informed. CNN, the most trusted name in news.

ZAKARIA: We have explored a number of ways to create cheaper, greener energy, but experts often cite a fifth fuel as being just as important. Efficiency. What if we could get more mileage, more bang for our buck, for every kilowatt of energy we used?

One man shows us how we can save energy and money all from his banana farm.

(BEGIN VIDEOTAPE)

ZAKARIA (voice-over): Welcome to the jungle. But we're not in the tropics. We're more than 1,000 miles north in the rocky mountains of western Colorado.

ZAKARIA: During the day, the house runs on solar power. Lovins sells back any excess to the grid. Purchased wind power fuels the house at night and fully charged batteries serve as backup in case the grid goes down.

Lovins knows that most people won't build homes like his, but he insists we can start to save the earth and save money just by being a little more efficient in our energy use.

LOVINS: The U.S. could get completely off oil and coal by 2050 with a 2.6 bigger economy, and by the way, eliminate nuclear energy as well and use a third less natural gas. $5 trillion cheaper than business as usual. Not counting any hidden costs like carbon emissions.

ZAKARIA: In "Reinventing Fire" Amory Lovins and the Rocky Mountain Institute, his self-described think and do tank, lay out a blueprint for how the U.S. can achieve that goal and he says there is no need for government intervention. Because businesses would lead the effort and profit from doing it.

LOVINS: We found this would require no new inventions and no act of Congress because it could be led by business for profit, the $5 trillion on the table is ample inducement.

ZAKARIA: For example, we can save money by putting our gas guzzlers on a diet.

LOVINS: Over the past quarter century, they've gained weight twice as fast as we have. Two-thirds of the energy it takes to move a typical car is caused by its weight.

ZAKARIA: Trains, planes and automobiles burn over 13 million barrels of oil every day in the United States. And we spend over a billion dollars per day buying that oil, almost half of which comes from foreign countries, some of whom are considered national security problems.

LOVINS: Weaning ourselves off oil saves about $4 trillion net present value in the United States. That money then stays at home.

ZAKARIA: So, Lovins reasoned, what if we wasted less fuel getting gas to the wheels. And he designed the hypercar, which could weight about 2/3 less than a normal car and could run up to an astonishing 240 miles per gallon. It would be made of carbon fiber parts like this one.

ZAKARIA (on camera): Amory Lovins says this carbon fiber cap that he showed us, you took a sledgehammer to it?

FRIEDMAN: Yes.

ZAKARIA: Why?

FRIEDMAN: Well, I wanted to see if actually it could hold up, you know, to a car accident.

ZAKARIA (voice-over): "New York Times'" columnist Tom Friedman's attempts to whack, jump on and demolish the parts were unsuccessful. And Lovins believes carbon fiber is durable and light enough to revolutionize the auto industry.

Fiber porch, a for-profit spin off of the Rocky Mountain Institute.

FRIEDMAN: This is a lightweight seat frame we worked on.

ZAKARIA: Is taking that bet, manufacturing the type of carbon fiber parts that would ultimately be used in a hypercar.

FRIEDMAN: These materials absorbed more energy per unit pound than aluminum or steel. So your cars not only are going to be lighter, they also will be safer.

ZAKARIA: If hypercars sound like science fiction to you, Volkswagen and BMW will start producing their versions of hypercars next year.

And it's not just cars. Buildings can get a lot more energy efficient, too. If America's 120 million buildings were a country, they would use more energy than every country in the world except for the United States and China. A lot of that comes from densely populated cities like New York where Lovins have retrofit the Empire State Building.

LOVINS: We were able to get the 6,514 windows remanufactured on site into superwindows that let light through to block heat and then combining that with better lights and office equipment and so on, cut the maximum cooling load by a third. ZAKARIA: And all that energy savings also saved over $17 million. So no matter what your values are, Amory Lovins argues, energy efficiency is simply a good deal.

LOVINS: Whether you care most about profits and jobs or about national security, you don't need to believe the climate science. Let's just focus on outcomes not motives and then we can turn gridlock and conflict into a unified solution to our energy challenge.

(END VIDEOTAPE)

ZAKARIA: We can't all turn our living rooms into tropical oasis. But we can turn Amory Lovins' ideas into public mandates. Big business can make big profits, after all saving energy saves money that goes straight to the bottom line. Consider the impact that just two steps could have.

One move over to energy efficient bulbs and appliances. A 1.8 percent reduction in our residential electricity use can save $40 billion annually. According to the Environmental Defense Fund. Two, maximize energy efficiency in the industrial center. A 2009 McKenzie and Company report says that an upfront investment of $113 billion would unlock savings of $442 billion between 2009 and 2020.

Overall McKenzie estimates that the United States can save more than $130 billion annually and $1.2 trillion by 2020 just by maximizing efficiency.

Up next more of my thoughts on the whole energy debate.

(COMMERCIAL BREAK)

ZAKARIA: We cannot live without energy. It is what makes the modern world possible. For most of history, our only energy source was our labor and that of animals. That isn't enough. One example, a car uses the energy equivalent of the labor of 2,000 humans. Another is a jet plane. It uses the energy equivalent of 700,000 humans. So the first thing to admit is that we need lots of energy.

The second is to realize that for the foreseeable future, we will be dependent on fossil fuels. In 2010, the U.S. got 83 percent of its energy from fossil fuels. In 2035, despite great increases in efficiency, the U.S. government says we will still get 77 percent of our energy from fossil fuels.

That leads to a few conclusions. We need more renewable energy. Today renewable energy gives us 10 percent of our electricity. By 2035 that will rise to 16 percent. We should try to move towards it faster. But even if we were to succeed, we would still need to use fossil fuels for the majority of our energy needs.

Governments around the world, including the United States, have provided enormous help to the fossil fuel industry. In many ways from building out the infrastructure that it uses to protecting our supplies of oil from the Middle East. Even fracking, by the way, was developed with the help of the Department of Energy. So it is perfectly sensible to say that government should provide some support to the technologies of the future as well.

That support should mainly go towards research that would lead to technological breakthroughs, but we should also help these nascent industries, wind and solar, to achieve scale just as we helped the computer industry in the 1950s and 1960s. But having done all that, it is clear we will still need fossil fuels for the majority of our energy for decades to come.

That means choosing among them. And when natural gas replaces coal, you end up with a win-win. It is cost competitive and it emits half the carbon dioxide emissions of coal.

The conversation about fracking cannot take place without considering what would happen if we did not get that energy from shale gas. We would get it from coal, which is the dirtiest fossil fuel in existence.

We were all expecting a technological revolution in energy now. And we got one but not in renewables yet, rather in the extraction of hydrocarbons. It allows us to extract mountains of natural gas. Fracking should be studied carefully. It needs regulation, but we should also recognize that this might be the bridge fuel to our eventual goal -- cheap energy with zero emissions.

Finally there is one area where we really should all be able to agree. Energy efficiency. It's a no-brainer. It saves money and it involves no real sacrifice. When you go to a hotel in Europe, chances are that as you leave the room and take the hotel key out of its slot, the lights will go out.

Why can't we standardize that practice everywhere? An energy revolution would be great for the environment, but it would also be great for economic growth. Energy permeates every aspect of our lives, even more so than something like information technology. And you can see what a huge impact the information revolution has had on economic growth.

An energy revolution would be the next big thing we've all been looking for.

You can read more of my thoughts in a "TIME" magazine essay. Thanks for tuning in to this GPS special. You can always catch my regular show on Sundays at 10:00 a.m. and 1:00 p.m. Eastern. International viewers can go to our Web site for airtimes. CNN.com/fareed.